Does the 3DS version make the original N64 Version unplayable, is there a reason to play this again if you played the 3DS version?

The only reason would be to play the original in it's purest form.

I think it really depends. Do you think you'd be able to stomach the Water Temple again without the enhancements of the 3DS version?

Yes, I've done it a dozen times and I could easily do it again. I haven't played the 3DS version though, and if the only real gameplay change is a speedier trip through the water temple, I don't see what the big deal would be when playing the original.

Do you think you'd be able to stomach the Water Temple again without the enhancements of the 3DS version?

I think it really depends. Do you think you'd be able to stomach the Water Temple again without the enhancements of the 3DS version?

There's absolutely no reason to play the N64 version if you have this. I can't think of a single advantage that version has over this one.

I'm really thinking about dusting off my N64 to go back and play the original. I do it every few years, and it's still always a magical experience.